It's 10 o'clock on a balmy night in Alice Springs, and I am standing in a park with three Aboriginal youths who have just been detained for glue-sniffing. Stephen, Michael and Devon look disoriented. Devon, 12, says that he has not been home for four days. Jerry Doherty, my guide for the evening, explains: "They get hooked on glue. It can rot their brains and send them crazy.''

For the past three hours, I have been cruising in a van with Jerry and our driver, Victor Tapaya, around Alice and its Aboriginal camps. We are on Night Patrol, started a few years ago by the local Tangentyere Aboriginal Council to stop the public drunkenness and violence, which leads thousands of their people into prison cells. It has been a huge success, with Aborigines taking control of their own welfare.

To many Australians, the Northern Territory has always meant booze as much as heat, red dust and Ayers Rock. It has been renowned as one of the world's hardest-drinking places:people drink 50 per cent more than the Australian average, 80 per cent of 17-year-olds drink regularly and alcohol is involved in half of road deaths. While many remote, tribal Aborigines have shunned alcohol, for those in a town like Alice, booze has been the fatal link in a disastrous cycle of unemployment, bad health and imprisonment.

Much of this is starting to change, thanks to the Night Patrol. When I turned up at its headquarters in an Alice Springs back street last Tuesday, two young people were taking calls from the police, civilians and some of the 10 Aboriginal camps strung along the Todd river. On hearing of trouble from drunkenness and fights, they sent their fellow Aborigines, dressed in yellow Night Patrol T-shirts, to sort it out before the police intervened. On busy nights, calls come pouring in at one a minute.

But our first stop was to help a white man. Sidney, in his 60s, looked thin and worn-out, clutching his belongings in two plastic bags. He had been wandering Australia since he stopped working as a carpenter in 1982 and was planning to sleep the night in the park. "You don't do that in this town," Jerry told him. "You could end up dead." We drove him back to patrol headquarters, where he was offered a blanket and floor space. Then we headed for the camps. Jerry, the only white man on the patrol, is married to an Aboriginal. "We can link a stabbing among Aborigines to cultural overtones, such as a tribal `payback'," he told me. "White police might dismiss it as drunken domestic violence.''

Aborigines started the first Night Patrol in Tennant Creek, north of Alice, in 1988. That town had the worst relations between police and blacks of any in Australia, and alcohol-related crime had driven both sides to despair. It was the women who got the patrol up and running, because they and their children most felt such violence. Since the Alice Springs patrol began in 1991, the idea has spread and has helped to mitigate Australia's scandalously high rate of Aboriginal imprisonment. Except in extreme cases, drunks, whom police once would have thrown into cells, are driven to sobering- up centres for the night and given a severe dressing-down - usually by women.

The drinking way of life has changed for whites, too. Ever since the Northern Territory government doubled taxes on all forms of booze except low-alcohol beer, there has been a 42-per-cent drop in full-strength beer consumption and a fall of 26 per cent in alcohol-related road accidents. Light- beer sales are booming. Marshall Perron, the Territory's Chief Minister, who pushed the measure through parliament, said: "You won't stop a culture of drinking here in the tropics but I hope we can amend it so that `having a beer' means a light beer.''

There is hope in all of this, and also despair. When we met the glue- sniffing boys, I assumed the Night Patrol would sort out their problems but the police turned up and took them away. Later, I learnt one boy's mother had been ruined by alcohol and the other parents had lost control of their children. When I got home, I felt like more than a light beer.